Engine Instrument Systems practice questions

Answer: B) A Bourdon tube

• AIncorrect. This measures temperature.
• BCorrect. Pressure straightens the curved Bourdon tube, moving the pointer.
• CIncorrect. This is a remote indication method.
• DIncorrect. This measures level.

Answer: B) Degrees Celsius

• AIncorrect. That's fuel flow.
• BCorrect. Limits are published in °C.
• CIncorrect. That's N1 or N2.
• DIncorrect. That's manifold pressure.

Answer: D) Fan spool speed

• AIncorrect. This is not N1.
• BIncorrect. This is a quantity reading.
• CIncorrect. That is N2.
• DCorrect. N1 is low-pressure spool (fan) speed, often a thrust-setting parameter.

Answer: A) That cylinder is misfiring or not firing, such as from a fouled plug or faulty ignition lead

When one cylinder's EGT is far below otherwise matching cylinders, that cylinder is probably not burning its charge, for example because of a fouled plug, a bad lead or a fuel delivery problem. Mixture or timing faults affect all cylinders together.

• ACorrect. If a cylinder burns little or no fuel/air charge, little heat reaches its exhaust, so its EGT probe reads well below the others. Check that cylinder's plugs, ignition leads and fuel delivery.
• BIncorrect. A rich mixture setting lowers EGT on every cylinder fed by the mixture control, not on just one while the others stay close together.
• CIncorrect. Retarded timing affects every cylinder and tends to raise EGT, because combustion is still going on as the exhaust valve opens. It would not single out one cylinder with a low reading.
• DIncorrect. A restricted oil cooler shows up as high oil temperature. It does not make one cylinder's exhaust gas temperature drop.

Answer: D) Show if the glass has rotated

• AIncorrect. That isn't its purpose.
• BIncorrect. That's the red line.
• CIncorrect. That's the yellow arc.
• DCorrect. A white index line reveals movement.

Answer: C) Dampens pulsations and limits leakage

• AIncorrect. That isn't its role.
• BIncorrect. It doesn't change engine pressure.
• CCorrect. It also limits oil loss if the line breaks.
• DIncorrect. That's a temperature probe.

Answer: C) Pounds per hour

• AIncorrect. That is a temperature unit.
• BIncorrect. That is a pressure unit.
• CCorrect. Mass flow in pounds per hour reflects energy delivered.
• DIncorrect. That is a speed indication.

Answer: B) Between the high-pressure (gas generator) turbine and the low-pressure turbine

ITT is sensed between the high-pressure and low-pressure turbines; on free-turbine engines, that is between the compressor turbine and the power turbine. TIT is measured ahead of the first turbine stage, and EGT is measured after the last one.

• AIncorrect. Gas temperature entering the first-stage turbine inlet guide vanes is turbine inlet temperature (TIT), not ITT.
• BCorrect. ITT is the gas temperature between the high-pressure turbine and the low-pressure turbine. On a free-turbine engine, that is between the compressor (gas generator) turbine and the power turbine.
• CIncorrect. A probe after the last turbine stage measures exhaust gas temperature (EGT), also called turbine outlet temperature, not interstage temperature.
• DIncorrect. This location gives compressor discharge temperature, which is upstream of combustion and of the turbines.

Answer: A) A magnetic pickup

• ACorrect. Gear teeth passing it produce pulses.
• BIncorrect. That measures pressure.
• CIncorrect. That measures temperature.
• DIncorrect. That measures level.

Answer: B) Individual engine gauges and separate warning and caution lights

EICAS combines engine parameter indications and crew alerting (warning, caution and advisory messages) on electronic displays. It replaces the separate engine gauges and annunciator lights of older cockpits.

• AIncorrect. Weather radar and terrain information usually appear on the navigation display (EFIS), not on the EICAS engine and alerting displays.
• BCorrect. EICAS (engine indicating and crew alerting system) shows primary and secondary engine parameters on electronic display units, along with warning, caution and advisory messages. This replaces the many separate engine gauges and annunciator lights found in older cockpits.
• CIncorrect. Attitude and airspeed are shown on the primary flight display, which is part of the EFIS, not on EICAS.
• DIncorrect. Route and navigation database information is handled by the flight management system and its control display unit, not by EICAS.